Retractable syringe

ABSTRACT

An automatic retractable syringe comprised of a syringe inside a compressed spring loaded locking safety sheath that moves into a protective position over the needle of the syringe that is triggered by the depression of the plunger, causing the positional locking mechanism to displace from its initial position and activate a compressed spring that expands, moving the locking safety sheath into its protective position and locks the sheath, preventing further movement of the locking safety sheath. An optional fusing system acts to permanently fix the locking mechanism in place to further secure the locking safety sheath in the protective position.

BACKGROUND OF THE INVENTION Field of Endeavor

An automatic, single use, retractable syringe, also known as a retractable safety syringe. This invention relates to a syringe with safely features to protect the handler from being injured by the needle after use. The field that most suits this invention and its applications is the Medical Field. This retractable syringe would be most appropriately used in the medical field, and for distribution to those suffering from drug addiction, requiring a syringe that automatically locks in a protective position for the safety of others. This retractable syringe is used for the injection of materials into humans, animals, or for use when a syringe is required and a potential danger or contaminant risk from the syringe is probable.

Background of the Art

With the increase in transmission of diseases from needle sharing due to the rising opioid crisis, there has been a strong movement to supply clean needles to those suffering from drug addiction. Unfortunately, this has resulted in an increase in discarded infectious needles in parks and other public areas that create a significant danger to the general public. The spread of infectious diseases, such as AIDS and Hepatitis can occur when an infectious needle from a drug user is discarded in a public area and comes into contact with the general public in a number of ways. The dangers to public safety regarding this issue are very well known and documented.

The dangers of a discarded infectious needle injuring a member of the public is a growing problem, as more needles are handed out to drug users to prevent cross infection between drug users due to needle sharing. Among the most vulnerable in the population to be in danger of contact with a discarded infectious needle are children, custodians, parks workers, garbage men, and other civil servants, as children may not be able to identify the danger, and custodians, parks workers, and other civil servants are often challenged with the task of removing and disposing of the discarded needles.

The increase in the number of discarded syringes and the frequency of contact with them in cities and towns is quickly becoming an epidemic and has resulted in the need for syringes that can be handled safely when they are improperly discarded after use.

There are several different retractable needles that have been developed, but many of these designs have failed to make it to market, as they are too complex in design, are too expensive to make, or have design flaws that cause the needle to retract too quickly causing injury to the user, or have design flaws that impede the proper functions of the syringe.

Many of the retractable needle designs that have been patented have opted for an internal locking mechanism, which is a design that poses several problems. For example, in order to design a retractable syringe with a locking mechanism that is built into the syringe, many of the working parts have to be very small in order to fit the locking mechanism into the small spaces inside the syringe itself. These tiny parts can be subject to structural failure.

In addition, the increase of surface area and the mechanics involved with constructing these syringes can result in increased chance of contamination of the syringe during the process of manufacturing the syringes and this can also create weak points in which leaking from the barrel and other areas of the syringe can occur.

Among the most common deficiencies in the design of retractable syringes in the past has been that of problems regarding reliability, complexity, ease of use, and cost, as these syringes have to be mass-produced by the millions. The need for high speed production of syringes demands a design that is easily molded and assembled, which means that retractable syringes with numerous small internal parts requiring extensive effort to assemble are not likely to be produced at a competitive cost.

PRIOR ART

Regarding prior art, there are many retractable syringe designs available, Each of these designs have some general and obvious features that are related to each other. For example, they all contain a plunger with a rubber plunger head, barrel, needle adapter, needle hub, needle or shaft with a beveled end, measurement scale, finger flange, and a protective cover, all of which are implied and understood as part of the basic and obvious features of a syringe, and are understood as obvious features of this invention.

Further to this, many of the prior art utilize the obvious component of a compressed spring as a method of automatic retraction for retractable syringes.

The first true hypodermic needle was created by Alexander Wood in 1853 and its use became widely used by the medical community shortly after. Since then, hypodermic needles have been significantly improved in efficiency, usefulness, and safety of use. The materials that are used to make syringes have also changed during this time in order to prevent leaks and reduce chances of infections, in order to make the device more reliable. In the late nineteenth century, biocompatible materials, such as improved plastics, rubber, and glass were developed to further improve the safety and efficacy of the syringe.

Prior art has not mentioned the use of a retractable syringe for the safety of the public after the user has discarded the syringe in an area in which the general public may come into contact with it and become contaminated through secondary handling of the syringe.

The designs of prior art are more complex than this invention, making them more difficult to manufacture and therefore more expensive to make due to small and delicate parts as a consequence of their internal design, where the locking mechanism and retraction occurs inside the small area at the front of the barrel.

The design of prior art, having the components of the locking mechanism inside the barrel increases the internal surface area in which contamination might form and may reduce the sterile conditions of the interior working parts of the syringe, which is not the case with this invention, as the mechanisms that cause retraction do not interfere with the normal operation of the syringe.

Prior art fails to address the need for a retractable syringe to be identifiable by sight for safety reasons. Many of the prior art cannot readily be identified by sight alone, as the working parts of the syringe are internalized and this reduces the ability to discern them from a conventional syringe.

Prior art has shown difficulty designing an effective way of controlling the retraction of the syringe with minimal effort in order to prevent splatter and backsplash, or pain from needle retraction while the needle is still in the patient.

Prior art has failed to introduce a design for a fusing system to permanently fix the needle in place subsequent to use of the syringe in order to ensure the locking mechanism will not come undone and cause the needle to become exposed.

There are several differences between prior art and this invention, such as the internal design of the retraction method compared to the external design of this invention and the use of the optional fusing system that prior art does not have. Several of the prior art use different methods of retraction and locking of the needle.

Notable differences prior art uses are, use of an air bleed hole to control retraction force, Luer-lock thread designs, using a needle tilt method of locking, which can be unreliable as the needle could dislodge, Plunger locks, internal mechanisms with side plunger designs, no optional fusing system, no locking safety sheath, one piece design, different locking mechanisms, situating the barrel on the side instead of being in line with the syringe in design, dual chamber designs, and the use of gas to retract the needle instead of using a spring.

Prior art found having relation in relevance to this invention are listed below:

Pat. No. Invention Title in The Canadian Patents Database 2,111,208 Syringe with retractable needle and closed barrel 2,356,199 Retractable hypodermic needle assembly and method for making the same 2,178,937 Retractable syringe with a closed barrel 2,780,168 Clinical Syringe 2,142,731 Retractable syringe with a closed barrel 2,797,207 Syringe Barrel Adapter and Needle Assembly 2,548,187 Retractable Syringe 2,218,478 Tamperproof Retractable Syringe 2,920,509 Retainer for Retractable Needle Assemblies and Syringes 2,692,968 Prefilled Retractable syringe, Plunger and Needle Assembly 2,835,950 Modular Gas-Actuated Retractable Needle Assembly 2,784,437 Retractable syringe with improved Delivery Efficiency and Locking system 2,621,479 Single Use Safety Syringe Having a Retractable Needle 2,838,559 Prefilled Retractable Syringe, Plunger and Needle Assembly 2,779,731 Vaccination Syringe. 2,894,138 Prefillable Auto-Retractable Safety Syringe 2,607,836 Improved Controlled Retraction Syringe and Plunger Therefor 2,406,567 Single Use Syringe 2,554,196 Retractable Syringe with Plunger Disabling System 2,107,631 Retractable Syringe 2,621,480 Single Use Safety Syringe Having a Retractable Needle 2,605,115 Controlling the Retraction of a Needle in an Auto Retractable Syringe 2,854,648 Improved Retractable Syringe Needle 2,762,847 Syringe Adapter * 2,963,334 Retractable Syringe 2,093,217 Retractable Syringe 2,845,362 Auto-Injector for Retractable Syringe 2,437,415 Retractable Syringe with Reduced Retraction Force 1,328,388 Disposable Retractable Syringe 2,843,477 Automatic Reconstitution for Dual Chamber Syringe 2,731,117 A Retractable Syringe 2,348,984 Hypodermic Syringe with Selectively Retractable Needle 2,604,322 Controlled Retraction Syringe and Plunger Therefor 2,559,089 Single Use Retractable Syringe 2,829,372 Retractable Syringe with Locking Plunger 2,829,355 Retractable Syringe with Segmented Retaining Ledge 2,601,431 Auto Retractable Syringe 2,806,218 Dual Chamber Syringe with Retractable Needle 2,930,095 Dual Chamber Syringe with Retractable Needle 2,806,216 Dual Chamber Syringe with Retractable Needle 2,806,215 Dual Chamber Syringe with Retractable Needle 2,806,036 Dual Chamber Passive Retraction Needle Syringe 2,914,028 Actuation Mechanisms for Dual Chamber Mixing Syringes 2,107,659 Retractable Syringe ETC Needles 2,580,092 Single Use Pneumatic Safety Syringe with Retractable Needle 2,862,880 Plunger Sub-Assemblies and Auto-Injectors Having Low Retraction

SUMMARY OF THE INVENTION

An automatic retractable syringe comprised of a syringe inside a compressed spring loaded locking safety sheath that moves into a protective position over the needle of the syringe utilizing a positional locking mechanism on the side of said safety sheath that in the open/ready (needle exposed) position retains said safety sheath with the needle of said syringe exposed for use, where the plunger does not trigger said locking mechanism when drawn outward from the barrel and when said plunger is depressed, the bottom of the plunger top depresses the mechanism trigger, closing the gap at position A and forcing said locking mechanism out of said position A, causing said locking mechanism to be under tension while displaced and the spring to expand and the locking safety sheath to move into its protective position, where a portion of said locking safety sheath covers the needle, causing said locking mechanism to move to position B, where said locking mechanism then locks in place in position B, preventing said locking safety sheath from further movement, said position B comprises an optional fusing system, said fusing system is comprised of an adhesive or bonding chemical contained in a protective but breakable coating, said locking-mechanism is protected by a tamperproof encasement, said needle is covered by a removable needle cap prior to use, said locking safety sheath is also comprised of a viewing port to enable clear viewing of the measurement notches on the syringe, a safety tab to prevent the safety feature of the retractable syringe from being triggered prior to use, stoppers to prevent the syringe from being separated from the safety sheath, and stabilizer guides to enable smooth and stable movement of the sheath and syringe and related moving parts in relation to each other, said safety syringe also comprises other basic components of a syringe, such as a needle adapter and needle hub.

OBJECTIVES OF THE INVENTION

The main objectives of this invention, is for use as a disposable safety syringe for distribution to those suffering from drug addiction, in order to protect others from injury or infectious disease from discarded infectious syringes, and for use as a safety precaution against injury or transmission of disease or contaminant in any situation where a syringe is required.

DESCRIPTION OF DRAWINGS

FIG. 1 shows the retractable syringe in its open/ready, or needle exposed position, where the locking mechanism (3) is located in position A (11) prior to use. The plunger of the syringe can be pulled outwards in order to draw materials into the barrel of the syringe without causing the locking mechanism to activate. When the plunger is depressed, it makes contact with said mechanism trigger (2), which activates the locking mechanism (3).

FIG. 2 shows the retractable syringe in its activated position, where the plunger (1) is depressed, and said mechanism trigger (2) has closed said position A (11), causing said locking mechanism (3) to be displaced and under tension. With the displacement of said locking mechanism from position A, the spring (8) is now activated and begins to expand. The locking safety sheath (4) can now move to its protective position, where it will cover the needle. The locking mechanism (3) can now move to protective position B (12).

FIG. 3 shows the retractable syringe in its needle retracted position. The locking mechanism (3) has moved to position B (12) and the locking safety sheath (4) is now covering the needle (9) and is locked in place. When the optional fusing system (15) is utilized, said locking mechanism will now be permanently fixed in place at said position B (12).

FIG. 4 shows the viewing port (16), safety tab (17), Stoppers (18), and stabilizer guides (19), which are not expressed in FIG. 1, 2, 3, or 5.

FIG. 5a and FIG. 5b and demonstrates two of the possible variations of this locking mechanism and is meant to demonstrate that variations of this locking mechanism are possible. FIG. 5a and FIG. 5b are not intended to limit the many variations of this positional locking mechanism, as other variations are possible and should be included under the protection of this patent.

FIG. 5a shows said locking safety sheath as seen from the front view, wherein said locking mechanism, mechanism trigger, and all said related parts that aid in the action and positioning of said locking mechanism and the movement of said locking safety sheath are situated perpendicular relative to the safety locking sheath as seen in FIGS. 1, 2, and 3.

FIG. 5b shows said locking mechanism and related parts in an alternative design configuration, wherein said locking mechanism and related parts are positioned to the right (or can be arranged in a different variation or position) in design, allowing the locking mechanism and related parts to permit a slimmer design without changing the basic design concepts of said locking mechanism, locking safety sheath, and retractable syringe.

FIGURE LEGEND

FIGS. 1, 2, 3, 4, 5 a, and 5 b contain a numbered listing of parts for the retractable syringe. The numbered parts are as follows:

-   1 Plunger -   2 Mechanism Trigger -   3 Locking Mechanism -   4 Locking Safety Sheath -   5 Barrel -   6 Needle Adapter -   7 Needle Hub -   8 Spring -   9 Needle -   10 Plunger Top -   11 Position A -   12 Position B -   13 Tamperproof Encasement -   14 Needle Cap -   15 a and 15 b Optional Fusing System     -   15 a Adhesive or bonding chemical     -   15 b Protective coating -   16 Viewing port -   17 Safety Tab -   18 Stoppers -   19 Stabilizer guides

DESCRIPTION OF THE INVENTION

An automatic retractable syringe comprised of a syringe inside a compressed spring loaded locking safety sheath (4) that moves into a protective position over the needle (9) of the syringe utilizing a positional locking mechanism (3) on the side of said safety sheath that in the open/ready (needle exposed) position retains said safety sheath with the needle of said syringe exposed for use, where the plunger (1) does not trigger said locking mechanism when drawn outward from the barrel (5) and when said plunger is depressed, the bottom of the plunger top (10) depresses the mechanism trigger (2), closing the gap at position A (11) and forcing said locking mechanism (3) out of said position A (11), causing said locking mechanism (3) to be under tension while displaced and the spring (8) to expand and the locking safety sheath (4) to move into its protective position, where a portion of said locking safety sheath covers the needle, causing said locking mechanism to move to position B (12), where said locking mechanism then locks in place in position B (12), preventing said locking safety sheath from further movement, said position B (12) comprises an optional fusing system (15 a and 15 b), said fusing system is comprised of an adhesive or bonding chemical (15 a) contained in a protective but breakable coating (15 b), said locking mechanism is protected by a tamperproof encasement (13), said needle is covered by a removable needle cap (14) prior to use, said locking safety sheath is also comprised of a viewing port (16) to enable clear viewing of the measurement notches on the syringe, a safety tab (17) to prevent the safety feature of the retractable syringe from being triggered prior to use, stoppers (18) to prevent the syringe from being separated from the safety sheath, and stabilizer guides (19) to enable smooth and stable movement of the sheath and syringe and related moving parts in relation to each other, said safety syringe also comprises other basic components of a syringe, such as a needle adapter (6) and needle hub (7).

This invention is distinct in comparison with prior art, as it has a unique automatic locking feature that is triggered simply by expelling the contents of the barrel with the depression of the plunger that causes the needle to retract only when the user releases the thumb pressure applied to the plunger top. The movement of the locking safety sheath works in such a way that the needle is covered by a portion of the locking safety sheath when it locks into place at position B. Prior art has been previously designed such that the needle retracts into the syringe itself. This invention is unique in that the needle does not retract into the barrel of the syringe, but instead the method of retraction occurs through the movement of the safety locking sheath over the needle. The various safety features, such as the automatic locking safety sheath, helps protect from injury, or infectious diseases the syringe may be contaminated with. The locking safety features of this retractable syringe are unique to other prior art and is an improvement over other attempts to create a retractable syringe for safety purposes, as this safety syringe is designed to be used by not only those in the field of medicine, but also by people who do not have adequate medical training. Once locked, the syringe can be handled safely without the risk or danger of injury. The process of making this retractable syringe will be similar to that of making any other style of hypodermic needle or syringe. The needle is produced from steel that is heated and formed to make the needle, and a bevel is formed on the end during this process. Some needles are formed by using a die casting.

There are various ways that the barrel, plunger, and locking safety sheath can be made, including extrusion and injection molding. Assembly of the syringe is carried out using specialized automated machines and/or manually. After assembly, the syringes are put into packaging in order to keep them sterilized prior to use.

The simplicity of the design of this retractable syringe will make this invention less expensive to make compared to prior art and this design incorporates the mechanism parts on the outside of the syringe in order to ensure the syringe maintains its autonomy to minimize internal surface area in which contamination might be able to form in order to create the most sterile conditions possible for the interior working parts of the syringe.

This invention makes it easier for the handler to identify the syringe as a proper safety syringe simply by sight, due to the external design of the locking safety sheath, whereas other designs cannot readily be identified by sight alone.

This invention also allows the user to control the retraction of the syringe with minimal effort, as the force used to depress the plunger and activate the locking safety sheath transfers automatically to countering the force released by the compressed spring.

This invention prevents splatter or backsplash, and will significantly reduce pain due to the retraction of the needle as the function of the needle is autonomous to the locking mechanism and safety sheath and therefore can operate independently without the design of the locking mechanism and safety sheath impeding on the function of the syringe.

The design of this invention allows it to be identifiable by sight for safety reasons. Finally, the design of this invention protects the handler of a used retractable syringe in order for the syringe to be discarded safely. 

1. A retractable syringe wherein, said retractable syringe is comprised of a syringe barrel (5) with open forward and rearward ends comprising two areas on the side of the barrel, position A (11) and position B (12), in which said locking mechanism (3) is positioned without being under tension, a plunger (1) in the barrel with one end of the plunger extending out the rearward open end comprised of a plunger top (10), said syringe is also comprised of a needle (9), with needle huh (7), and needle adapter (6) into the forward end of the barrel, a protective needle cap (14), a spring loaded locking safety sheath (4) that is triggered when said plunger is depressed and the underside of said plunger top (10) presses down and activates said mechanism trigger (2), a viewing port (16) on the side of the locking safety sheath to allow proper measurement of materials into the barrel of the syringe, a safety tab (17) to prevent activation of the locking mechanism during transport and prior to use, stoppers (18) to prevent separation of the syringe from the locking safety sheath, and stabilizer guides (19) to ensure smooth movement of said syringe and said locking safety sheath in relation to each other, wherein said locking safety sheath has a locking mechanism (3) that comes under tension when it is displaced out of said position A (11), when said mechanism trigger causes position A (11) to close, the displacement of said locking mechanism activates the compressed spring (8) allowing said spring to expand, and said locking mechanism and the locking safety sheath it is attached to then move downward, causing said needle to retract, said locking mechanism moves to position B (12) and the tension said locking mechanism is under releases, as said locking mechanism moves into the gap provided by position B (12), said locking mechanism is then locked in place by said position B, as it cannot move up or down, said position B (12) comprises an optional fusing system (15 a and 15 b) as an added safety measure, said optional fusing system (15 a and 15 b) is comprised of an adhesive or bonding chemical (15 a) contained in a protective but breakable coating (15 b), said protective coating breaks as said locking mechanism (3) enters said position B (FIG. 3) and makes contact with said protective coating, said adhesive is released when said protective coating breaks, said adhesive fuses said locking mechanism to position B preventing further movement, said locking safety sheath is now in a position in which the needle is no longer exposed and the user is now protected from injury from the needle, said locking mechanism (3) is encased in a tamper proof encasement (13) to prevent tampering of the locking mechanism and to aid in the stability and strength of said locking mechanism, said locking mechanism and related components can exist in plurality.
 2. A retractable syringe as claimed in claim 1 wherein, said locking safety sheath (4) comprises a locking mechanism that acts as a spring (3) that comes under tension as the last of the contents from the syringe barrel are administered and is activated by the downward movement of said plunger top (10) and said mechanism trigger (2) closing the space in position A (11) and causing the locking mechanism to be displaced out of said position A (11) and conic under tension, said locking mechanism returns to its original position when the tension from being displaced is released by said position B (12) when said locking mechanism moves down to and enters position B (12) (FIGS. 2 and 3).
 3. A retractable syringe as claimed in claim 1 wherein, said plunger (1) has one end located inside the barrel and when said plunger is pulled upwards, draws the contents to be administered into the available space in the barrel (5) of the syringe without activating said mechanism trigger (2), and when said plunger is depressed and reaches the bottom of said barrel, the contents of said barrel will have been administered completely and said mechanism trigger (2) will be activated.
 4. A retractable syringe as claimed in claim 1 wherein, said spring (8) that was compressed and under tension when said locking mechanism was in position A (11) is activated and expands when said locking mechanism (3) is displaced from said position A (11) and the pressure applied to the plunger top (10) is released, said expanding spring causes said locking safety sheath (4) to move downward causing said needle (9) to be covered by a portion of said locking safety sheath and causing the locking mechanism (3) to move downward and into position B (12) releasing the tension it was under from the displacement of said position A (11).
 5. A retractable syringe as claimed in claim 4 wherein, said locking mechanism (3) is locked into place by position B (12) situating said locking safety sheath (4) in a protective position over said needle and locking said safety sheath in place.
 6. A retractable syringe as claimed in claim 1 wherein, a tamper proof encasement (13) covering the locking mechanism (3) protects the locking mechanism from being damaged or tampered with and aids in the stability and strength of said locking mechanism.
 7. A retractable syringe as claimed in claim 1 wherein, said needle (9) is covered by a removable protective needle cap (14) that is removed and discarded prior to using the syringe
 8. A retractable syringe as claimed in claim 1 wherein, the contents inside said barrel (5) move through said needle (9) that is attached to the syringe via a needle hub (7) and needle adapter (6) and into the patient as said plunger (1) moves downwards and said plunger lop (10) makes contact with said mechanism trigger (2), activating said locking mechanism (3) and said locking safety sheath (4).
 9. A retractable syringe as claimed in claim 1 wherein, said locking safety sheath (4) has a viewing port (16) on the side of the safety sheath in an area not occupied by said locking mechanism, that allows the user to view the measurement markings on the side of the syringe in order to draw an accurate measurement of liquid into the barrel.
 10. A retractable syringe as claimed in claim 1 wherein, a safety tab (17) is attached to said plunger top (10) and to the locking safety sheath (4), in order to prevent premature activation of said locking mechanism during transport or prior to use, said safety tab is to be removed and discarded prior to using said retractable syringe (FIG. 4).
 11. A retractable syringe as claimed in claim 1 wherein, said barrel (5) of said syringe comprises two notched positions, Position A (11) in which said locking mechanism (3) is located in the open/ready, or needle exposed position (FIG. 1), and Position B (12) in which the locking mechanism moves towards and becomes positioned in when said locking safety sheath is in the closed/locked, or needle retracted position (FIG. 3).
 12. A retractable syringe as claimed in claim 1 wherein, said locking safety sheath (4) and said barrel (5) comprise stoppers (i 8) located on opposing sides, on said locking safety sheath and on said barrel of the syringe, said stoppers move towards each other when said locking safety sheath is activated, said stoppers act to prevent said syringe from being removed from said locking safety sheath (FIG. 4).
 13. A retractable syringe as claimed in claim 1 wherein, said locking safety sheath and said barrel comprise Stabilizer guides (19), said stabilizer guides aid in the stability of movement of said syringe inside said locking safety sheath and prevents binding while said locking safety sheath and said syringe are in motion.
 14. A retractable syringe as claimed in claim 1 wherein, said position B (12) comprises an optional fusing system (15 a and 15 b), said optional fusing system acts as an additional safety measure and can be used to secure any part of said locking safety sheath as an additional safety measure to prevent needle exposure, such as securing said locking mechanism in place at said position B through bonding or fusion, said position B and said locking mechanism and said locking safety sheath and said retractable syringe all function properly and work to retract said needle and lock said locking safety sheath in its protective position with or without the use of the optional fusing system.
 15. A retractable syringe as claimed in claim 14 wherein, said optional fusing system (15) is comprised of an adhesive or bonding chemical (15 a) contained in a breakable protective coating (15 b)
 16. A retractable syringe as claimed in claim 15 wherein, said protective coating (15 b) is comprised of material that keeps said adhesive or bonding chemical contained and in good order ready for use
 17. A retractable syringe as claimed in claim 16 wherein, said protective coating (15 b) is comprised of material that breaks when said locking mechanism (3) enters said position B (12)
 18. A retractable syringe as claimed in claim 17 wherein, said protective coating (15 b) breaks and releases said adhesive or bonding chemical (15 a) when said locking mechanism (3) enters said position B (12) and strikes said optional fusing system, or when a surface of said locking safety sheath comes into contact with a surface of said barrel containing said optional fusing system.
 19. A retractable syringe as claimed in claim 18 wherein, said adhesive or bonding chemical (15 a), once released, secures said locking mechanism in place at said position B (12), or contacted surface, preventing further movement of said locking mechanism and locking safety sheath.
 20. A retractable syringe as claimed in claim 1 wherein, said locking mechanism, mechanism trigger, and all said related parts that aid in the action of said locking mechanism and the movement of said locking safety sheath can be situated perpendicular relative to the safety locking sheath (FIG. 5a ), or can be positioned to the left or to the right by design (FIG. 5b ), or other configuration of this locking mechanism's design, allowing the locking mechanism and related parts to lay sideways, flat against said barrel and locking safety sheath to allow a slimmer design without changing the basic design concepts of said locking mechanism, locking safety sheath, and retractable syringe (FIGS. 5a and 5b ). 